wmavoicedec: use the checked bitstream, reader

Fixes out of array reads

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/wmavoice.c

@@ -25,8 +25,6 @@
  * @author Ronald S. Bultje <rsbultje@gmail.com>
  */
 
-#define UNCHECKED_BITSTREAM_READER 1
-
 #include <math.h>
 
 #include "libavutil/channel_layout.h"